Yellow acridinium dye and process of making same.



UNITED STATES Patented September 15, 1903.

PATENT OFFICE.

OTTO SOHST, OF HOOHST-ON-THE-MAIN, GERMANY, ASSIGNOR TO FARE WERKE,VORM; MEISTER, LUCIUS & BRUNING, OF HOCHST-ON-THE;- MAIN, GERMANY, ACORPORATION OF GERMANY.

YELLOW ACRIDINIUM DYE AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of. Letters Eatent No. 739,117, datedSeptember 15, 1903.

Application filed August 7, 1902- To all whom it may concern.-

Be it known that I, OTTO SOHST, Ph. D., a citizen of the Empire ofGermany, residing at Hochst-on-the-Main, Germ any, have invented certainnew and useful Yellow Acridinium Dyes and Process of Making the Same, ofwhich the following is a specification.

Dyestuffs of the acridinium series that is to say, those alkylated atthe acridin nitrogen have hitherto only been obtained by the action ofan alkyl halide, dimethyl sulfate, or para-toluenesulfonic acid ester oncertain amido-acridins--such, for instance, as acridin yellow,benzoflavin, (be. (American patent specifications Nos. 666,095 and666,096.) By the action of acid and alcohol on amido-acridins, however,alkylated acridin' dyestuffs are formed in the amido groups. (Englishspecification No. 8,872 of 1900, lines 40 to' 49.) I now have found aprocess which permits of alkylating simultaneously the acridin nitrogenand the amido groups. (The alkylation of the amido groups occurs ingeneral only partially.) This simultaneous alkylation is effected byheating to a high temperature the diluted aqueous acid solutions ofleuco compounds of acridin dyestuffs with alcohol. For the leucocompounds the corresponding methane bases may directlybe used but thenthe shade of the dyestuff obtained is often somewhat dull. The dyestuffsobtained in this manner have the general formula:

Serial No. 118,802. (Specimena) wherein R means hydrogen, phenyl,methyl, &c.; S, an acid radical, and X and Y hydrogen or alkyl.

The manufacture of these dyestufis alkylated at the acridin nitrogen andin the amido groups is easily carried out, as may be seen by thefollowing example: Two hundred and fifty grams of crystallizedmeta-toluylenediamin are disolved in about five hundred cubicseventy-five-per-cent. strength are slowly added at ordinary temperatureand stirred for ten to fifteen hours. The solution thus obtained is thentreated in a suitable closed vessel with two hundred and fifty grams ofconcentrated hydrochloric acid and heated for four hours to 1403centigrade. The mass having cooled to centigrade, one hundred and fiftygrams of methyl alcohol are added, and the whole is heated for from oneto two hours to 17 0 centigrade. Thus a clear feeble-yellow-coloredsolution is obtained, which when exposed to the air intensifies byoxidation. The latter is completed by adding a solution of one hun dred'andtwenty grams of ferric chlorid. It is then filtered, and the dyestuffis precipitated with zinc chlorid and common salt. The dyestuff mayfurther be purified by dissolving ten parts of it in about five hundredparts of hot water. The solution is then made alka= line and is filteredwhile being hot. The fil trade is again acidified with hydrochloric acidand the dyestuif is reprecipitated with zinc chlorid and common salt'..If a larger quantity of methyl alcohol is employedfor instance, threehundred grams instead of one hundred and fifty gramsand, if heated for alonger time, the shade of the dyestuff is of a somewhat redder tint.Generally ethyl al cohol yields a more yellowish dyeing product thanmethyl alcohol When dry and pulverized, the dyestuifs are brown-redpowders, readily soluble in water, dyeing cotton treated with tannin andleather yellow to orange-yellow. It is characteristic that from the hotdiluted aqueous solutions of their hydrochlorids the free bases are notprecipitated by ammonia, but only by causticsoda lye. The dyestuii's areinsoluble in ether and benzene, soluble with difficulty in alcohol. Inconcentrated sulfuric acid they dissolve to a greenish-yellowcoloration, and on addition of water an orange-yellow solution isobtained.

Having now described my invention, What I claim is-- 1. Theherein-described process for the manufacture of yellow to orange-yellowdyestuffs of the acridinium series being not only alkylated at theacridin nitrogen but also partially in the amido groups, which consistsin heating the leuco compounds of amido-acridin dyestuffs in a solutionof dilute hydrochloric acid with alcohol to a high temperature and inoxidizing them afterward, substantially as set forth.

2. As a new product a yellow to orange-yellow dyeing dyestulf having theformula:

trated sulfuric acid to a yellow coloration with I a green-yellowfluorescence; it dyes cotton treated with tannin and leather yellow toorange-yellow shades.

In testimony that I claim the foregoing as my invention I have signed myname inpresence of two subscribing witnesses.

OTTO SOI-IST.

Witnesses V ALFRED BRIsBoIs, BERNHARD LEYDEOKER.

